A cohort of patients with chronic type B hepatitis have been followed regularly with frequent determinations of serum biochemical liver tests as well as serological markers of hepatitis B virus infection. Selected individuals have been entered into therapeutic trials of antiviral and immunomodulating therapies. Three forms of therapy have been investigated: 1) adenine arabinoside monophosphate (Ara-AMP), 2) recombinant DNA human leukocyte alpha interferon (IFN) and 3) corticosteroids. In a randomized controlled trial, a one month course of intramuscular Ara-AMP induced a temporary decrease in serum hepatitis B virus levels. However, long-term remissions in disease occurred in an equal percentage (20%) of treated and untreated patients. A further study using three ten-day courses of Ara-AMP yielded a similar low rate of permanent responses (10%). A short course of high dose prednisolone therapy has been used to treat 18 patients with this disease as a part of a randomized, placebo controlled double blind study. None of the patients demonstrated a remission in disease activity. Multiple, two-week courses of IFN have been administered to eight patients. In follow-up, at least 25% of the patients have demonstrated apparent long-term responses to treatment.